This invention relates, generally, to suspensions for light duty trucks and similar vehicles. The suspensions make use of four air springs and two single leaf springs together with shock absorber systems. More particularly, the invention relates to such suspensions which will replace conventional vehicle axle suspensions of the type combining a leaf spring pack and a shock absorber system mounted on and below a fore-and-aft extending chassis frame member on each side of a vehicle, and with each leaf spring pack and its shock absorber system being attached to the adjacent end of an axle.
A suspension of the present invention can either be installed as original equipment on a vehicle such as a light duty truck or it may be installed to replace a conventional leaf spring pack and shock absorber system. In either case, the suspension of the present invention is unique in that it makes maximum use of (1) certain existing or already in place components used in a conventional vehicle axle suspension of the type combining a leaf spring pack and a shock absorber system and (2) existing air springs and related components which are standard in suspensions of the type that utilize air springs.
In the suspensions of the present invention single leaf springs provide the primary support for the load due to the empty vehicle and resist side thrusts and driving and/or braking torque end thrusts applied from the vehicle's axle. The four air springs provide the primary support for the portion of the total load which exceeds the load due to the vehicle when empty.
In view of the foregoing summary of the invention, it will be seen that the object thereof, generally stated, is the provision of a suspension for light weight trucks and similar vehicles that makes maximum use of conventional and standard components and known vehicle suspension designs and technology to provide a new, low-cost suspension system for light duty trucks and the like that addresses the user's concern for a softer ride through the entire range of empty and loaded vehicle conditions.
A further object of the invention is to incorporate in the suspensions new known height control systems which provide a constant ride height thereby requiring less rear wheel to fender clearance and permitting easier headlight aiming.
Certain other objects of the invention will be apparent to those skilled in the art from the following detailed description of the presently preferred embodiment taken in conjunction with the accompanying drawings wherein: